If this were an actual line feature store in a database instead of a graphic layer this issue will not occur as the street data would be digitized with good precision.

I think since the route is simply connecting the nodes to nodes it is not taking into consideration the curvature of the line feature and hence the there is a shift in certain locations when you zoom in.

Regarding the why it doesn’t show any shift when you are zoomed out might be due some feature curvature generalization that might have been applied.

Do post what are your findings I am sure there are many other users who would have the similar or probably the same query.